Photographic printing machine



June 21, 1932. A. s. HOWELL PHOTOGRAPHIC PRINTING MACHINE 14Sheets-Sheet l Filed June 20 June 21, 1932., s; HOWELL MW/NH" HUM June21, 1932. A. s. HOWELL PHOTOGRAPHIC PRINTING MACHINE Filed June 20. 192714 Sheets-SW61 3 June 21, 1932- A. s. HOWELL I PHOTOGRAPHIC PRINTINGMACHINE Filed June 20, 1927 14 Sheets-Sheet 6 June 21, 1932. A. s.HOWELL ,8

PHOTOGRAPHIC PRINTING MACHINE Filed June 20, 1927 14 Sheets-Sheet 7 June21, a HQNELL PHOTOGRAPHIC PRINTING" MACHINE Filed June 20, 1927 4Sheets-Sheet a five/afar warm Home/Z 6 Q June 21, 1932. HOWELL 1,863,657

PHOTOGRAPHIC PRINTING MACHINE Filed June 20, 1927 14 Sheets-Sheet 9lllll A WIIIIIIIIIIIIIIIIIIIIII" June 21, 1932. A. '5. HOWELL'PHOTOGRAPHIC PRINTING MACHINE Filed June 20 14 Sheets-Sheet 10 June 21,1932. A. s. HOWELL PHOTOGRAPHIC PRINTING MACHINE 14 Sheets-Sheet 11Filed June 20. 1927 June 21, 1932.

PHOTOGRAPHIC PRINTING MACHINE A. S. HOWELL Filed June 20, 1927 14Sheets-Sheet 12 June 21, 1932. A. s. HOWELL PHOTOGRAPHIC PRINTINGMACHINE Filed June 20. 1927 14 Sheets-Sheet 13 \QN kQ NQ RN June 21,1932. A. s. HCVDWELL PHOTOGRAPHIC PRINTING MACHZNE Filed June 20, 192714 Sheets-Sheet l4 UNITED STATES PATENT ALBERT S. HOWELL, OF CHICAGO,ILLINOIS, ASSIGNOR TO THE BELL d5 HQWEELL SGM- PANY, OF CHICAGO,ILLINOIS, A CORPORATION OF ILLINOIS PHOTOGRA IPHIC PRINTING MACHINEApplication filed June 20, 1927. Serial No. 200,163.

Myinvention relates particularly to mo;- tion picture film printingmachines of the optical type involving the spacing of the negative andpositive films and theinterposltion of a photographic lens therehetween,although certain features thereof are not limited to this type alone.

The invention has for its general object the provision of an efficientand conveniently controlled photographic printing machine with a viewtoward the production of prints of excellent quality and particularlywith a view toward the printing from the conventional 35 mm. film uponthe conventional 16 With this object in view my invention con-' andhaving parts removed and broken away;

Figure 2 is a rear elevation of the same; Figure 3 is an end elevationof the same; Figure 4 is a diagram of the electrical circuits embodiedin the machine; Figure 5 is an end elevation of the control indicatingdevice, hereinafter described, with parts broken away; a

, Figure 6 is a partial enlarged top plan view of the machine with partsremoved, broken away-and in section;

Figure 7 is an enlarged'partial section on the line 7--7 of Figure 6;

Figure.8 isan enlarged partialsection on 4 the line 8--8 of Figure 6;

Figure .9 is a diagrammatic view showing the timed relation of various1nstrumental1 ties of the machine;

Figure 10 is an enlarged partial section on the line 10-10 of Figure 3;

Figure 11 isa partial section on the line 1111 of Figure 10;

Figure 12 is a partial frontelevation of the machine with parts brokenaway, removed and in section;

Figure 13 is a similar view of a portion of the machine showing theparts in positions difi'erent from those in which they are shown inFigure 12;

Figure 14 is an enlarged partial sectional view on the line 14-44 ofFigure 6;

Figure 15 is an enlarged partial sectional view on the line 15-15 ofFigure 14:;

Figure 16 is a fragmentary rear View of portion of the mechanism;

Figure 17 is a sectional view on the line 17--17 of Figure 16;

Figure 18 is a partial section on the line 1818 of Figure 16;

Figure 19 is a partial view of the mechanism shown in Figure 17 andlooking to the ri ht therein and with a part broken away;

igure 20 is a sectional view substantially on the line 20-20 of Figure12;

Figure 21 is a partial enlarged sectional view on the line 2121 ofFigure 15;

Figure 22 is an enlarged intermediate view substantially on the line2222 of Figure 6;

Figure 23 is a partial view similar to Figure 22 showing a part brokenaway and showing the parts in different positions from those in whichthey are shown in Figure 22;

Figure 24 is an enlarged intermediate view substantially on the line2222 of Figure 6 but looking in a direction opposite that in-- dicatedby the arrows of this line;

F1gure 25 is a partial condensed sectional view substantially on theline 2525 of Figure 1; 7 Figure 26 is an enlarged partial section on theline 2626 of Figure 2;

Figure 27 is an enlarged partial sectional vlew on the line 27-27 ofFigure 12';

Figure 28 is an enlarged fragmentary front elevation of a portion of thepositive film guide of the machine and related parts, hereinafterdescribed, with a part broken away;

Figure 29 is an enlarged fragmentary front elevation of the positivefilm guide of the machine and related parts, hereinafter described, withparts broken away;

Figure 30 is an enlarged isometric projection of one of the parts shownin Figure 28, hereinafter described;

Figure 31 is an end elevation of the photographic lens supportingstructure of the machine, hereinafter described;

' Figure 32 is a front elevation of the structure shown inFigure withparts broken away, removed and in section; I

Figure 33 is an end elevation of a part of the lens carrying structure,hereinafter described;

Figure 34 is a top plan view of a portion of the lens carryingstructure, hereinafter described, with a part removed.

Like characters of reference indicate like parts in the various views.

Referring to the drawings, 1 designates supporting pedestal on the upperend of which a composite or assembled frame 2 is pivotally mounted forangular movement in a horizontal plane. See Figures 1, 2, 3, and 12.This frame is extended endwise of the machine in one direction at thelower portion thereof and mounted on this extended portion is anenclosed rheostat 3 of usual design which is manually adjustable bymeans of an exterior knob 4 provided with a pointer 5 cooperating with astationary scale 6 for indicating the adjustment of the rheostat. SeeFigure 6.

An upper portion of the frame 2 forms a light tight vertical lampchamber 7 within which is mounted, by means of a suitable socket 8forming the lower end of the lamp chamber and removably securedthereto,an incandescent electric lamp 9 of suitable design which provides theprinting light. See Figures 1, 2, and 6.

Another upper portion of the frame forms a cylindrical motor casing 11which is disposed in parallelism with the focal axis of the machinealongside the lamp chamber and at the rear thereof, and mounted withinthis motor casing, with its shaft 12 disposed in parallelism with thefocal axis of the machine, is an electric motor 13 for driving themachine. See Figures 3 and 6. The outer end of the motor casing isextended, and disposed within this end portion is a centrifugal speedgovernor consisting as follows. See Figures 10 and 11. A disklikefriction member 14 is carried with and is rotatably fixed with theoutwardly extending end of the motor shaft 12 and is axially movablewith respect thereto. This friction member is engageable withanon-rotatable friction member 15 which is carried for adjustmentaxially of the motor shaft on a removable cap 16 forming the outer endof the motor casing 11 and connected for manual adjust ment with amanually operable member 17 on the exterior of the .cap in a mannerunnecessary to be described. Axial positioning of the friction member 14is controlled by weighted levers 18, rotatably fixed with gaging anddisengaging movement.

the motor shaft and pivotally mounted for movement radially thereof andconnected with the friction member 14 to operate the same against thefriction member 15, and a spring 19 yieldably urging the friction member14 away from the friction member 15. The centrifugal force exerted uponthe weighted levers 18 engages the friction member 14 against thefriction member 15 with varying pressure whereby the speed of the motorshaft is uniformly controlled, adjustment of the speed of the motorbeing afforded by axial adjustment of the friction member 15;

The part of the upper portion of the frame 2 adjacent the inner end ofthe motor forms an enclosure within which is rotatably mounted a camshaft 21 which is disposed in parallelism with the focal axis of themachine. See Figures 6, 15, and 20. The shaft 21 is provided adjacentthe inner end thereof with a cam disk 22 on the face of which,corresponding with the adjacent end of this shaft, are positive clutchteeth 23. A hub 24 is mounted on the adjacent end of the shaft 21 foraxial movement with respect thereto and is rotatably fixed with theshaft by means of an axially extending pin 25 secured on the cam disk 22and slidably engaged in a corresponding bore in the hub. See Figure 15.A spur gear 26 is mounted on the hub 24 for rotation with respectthereto and isaxial- 1y fixed therewith, and is provided with clutchteeth 27 engageable with the clutch teeth 23, thus providing apositivedriving clutch for driving the machine. A spring 28 operates between thehub 24 and the shaft 21 to yieldably urge the gear 26 in the directionto engage the clutch, and the hub 24 is axially movable to move the gear26 for engagement and disengagement of the clutch.

spur gear pinion 29 is secured on the inner end of the motor shaft 12and meshes with the gear 26 for driving the machine through theaforementioned clutch, the gear 26 being slidable along the pinion 29for clutch en- The motor drive above referred to is fully described andclaimed in my I]. S. Patent No. 1,509,555, granted September 23, 1924,for improvement in electric motor drive and con-- trol means for motionpicture machines and the like, and requires no further description forpresent purposes.

The lamp chamber 7 is light confining and is provided at its lowerportion with an air inlet opening 31 and at its upper end with an airoutlet opening 32, and a forced air draft is maintained through the lampchamber during operation of the machine in the following manner. SeeFigure '6. Air impelling vanes 33 within the motor casing 11 are spacedabout the axis of the motor 13 and are disposed intermediate thefriction member 14 and the motor 13 and are secured to the frictionmember 14 for rotation with the motor shaft. See Figures 10 and 11. Theintermediate portion of the motor casing 11 bet-ween the vanes 33 andthe motor 13 is provided with openings 34, see Figures 2 and 6; whichcommunicate with the portion of the motor casing occupied by the vanesthrough openings in a spider carrying a bearing 36 of the motor shaft12. The motor casing 11 is provided with an outlet opening 37 overlyingthe vanes 33, and this outlet opening communicates with the inletopening 31 of the lamp chamber through an angular enclosed lighttrapping air passage 38. See Figures 6, 10, and 11. A second angularenclosed light trapping air passage 39 communicates at one end with theoutlet opening 32 of the lamp chamber and extends about the cylindricalmotor casing 11 and communicates at its other end with the atmosphere.See Figures 2, 3, and 6. When the motor 13 is operating the airimpelling vanes 33 draw air through the openings 34 of the motor casingand force it into the lamp chamber through the opening 37 of the motorcasing,

through the passage 38 and into the lamp chamber 7 through the inletopening 31 thereof. The air thus entering the lamp chamber is forcedupwardly therein and is then exhausted into the atmosphere through theoutlet opening 32 of the lamp chamber and the passage 39, the passages38 and 39 trapping light from the lamp chamber. Thus the lamp chamber 7and the lamp 9 therein are prevented from becoming overheated, thearrangement affording a compact design well adapted to the generalstructure shown.

The filament of the lamp 9 is centered with the focal axis of themachine, and the lamp chamber 7 is provided with a light opening, alsoalined with the focal axis of the machine, across which is disposed alight diffusing element in the form of a ground glass 41 which iscarried in a mounting 42 mounted in a transverse slide on the frame 2for removal of the ground glass for accessibility. See Figures 6, 14,and 15. The frame 2 has a vertical transverse wall 43, in front of thelight opening of the lamp chamber, which is a ertured at the focal axisof the machine. and an optical'condenser 44 is disposed in this openingin alinement with said focal axis for cooperation with the lamp andground glass 41 to effect a printing light, the condenser 44 beingcarried in a mounting45 mounted in a a transverse slide on the frame 2for accessibility.

A second frame 46 is mounted on the frame 2 for vertical adjustment withrespect to the frame 2 in the following'manner. The wall 43 and themechanism enclosing portion of the frame 2 form an angle and the frame46 is angled correspondingly and engages the angle of the frame 2 forvertical sliding movement with respect thereto, retaining plates 47 andadjustable bearing blocks 48 secured on the frame 2 and slidably engagedby the frame 46 retaining this frame in said angle of the frame 2.Pivotally mounted on the frame 2 is a horizontally disposed shaft 49which is operatively connected with the frame 46 by an eccentric 51 onthe shaft engaging aconnecting link 52 which is pivotally connected withthe frame 46, whereby angular adjustment of the shaft effects verticaladi justment of the frame 46 with respect to the frame 2. See Figures 1,14, 20, and 22. A lever 53 is secured on the shaft 49 and is providedwith a handle 54 for manual operation. An indexed segment 55 is mountedon the frame 2 and cooperates with the lever 53 to indicate adjustmentof the frame 46 with respect to the frame 2, there being provided means,unnecessary to be described, operating between the segment 55 and thelever 53 for releasably securing the shaft 49 in any adjusted positionfor correspondingly positioning the frame 46 with respect to the frame2.

The transverse wall of the frame 46 is apertured corresponding with thefocal axis of the machine, and carried with the frame 46 is a verticallyextending intermittent negative film feed guide including film faceguide members 56 and 57 provided with light apertures 58 correspondingwith the focal axis of the machine, the face guide member 56 beingsecured against the outer face of the transverse wall of the frame 46and the face guide member 57 being mounted for movement to and away fromthe guide member 56 in a manner hereinafter described. See Figures 14and 15.

Intermittent film feeding mechanism is provided for intermittentlyfeeding a negative film 59 in the aforementioned guide and thismechanism consists as follows. See Figures 12, 15, and 22. Secured onthe frame 2 is a pair of alined vertically spaced studs 61 studs 61 forpivotal movement and movement longitudinally thereof is a shuttle 62provided with a transverse opening 63 through which the cam shaft 21extends. cam 64 fast on the shaft 21 engages opposite horizontal edgesof the opening 63 of the shuttle to efiect vertical reciprocating orfilm feed and return movement of the shuttle with rotation of the shaft21, and a face cam 65 on the cam disk 22 engages projections 66, spacedin diametrically opposite relationwith respect to the studs 61, on theshuttle to effect film engaging and disengaging movement of the shuttle.The shuttle 62 is provided with a toothed QXtPIlSiOH 67 engageable Aradial with usual perforations of the film 59 in the q the block 71 in.er 73. A spring 74 It 'will be observed that the intermittent filmfeeding mechanism just described is carried by the frame 2 and that thecooperating negative film guide is carried by the frame 46, so thatadjustment of the frame 46 with respect to the frame 2 longitudinally ofthe film guide, as hereinbefore described, varies the relation of theaperture of the film guide longitudinally of the guide with respect tothe intermittent feeding mechanism, thus providing for framing in asimple and effe tive manner. I

Disposed in the angle of the frame 46 is a tubular light enclosingmember 68 disposed substantially coaxial Withthe focal axis of themachine, and this member is mounted on the frame 46 for movement withrespect thereto longitudinally of the focalaxis of the machine by meansof suitable anti-friction bearings 69. See Figures 14, 15, and 20.

The end of member 68 adjacent the lamp.

chamber 7 is extended vertically, and the face guide member 57 issecured on this end of the member 68 for movement therewith to and awayfrom the face guide member 56 secured on the frame 46 to open'and closethe guide, and movement of the member 68 with respect to the frame 46 iscontrolled as follows. See Figures 14 to 19 inclusive. A slide block 71is mounted on the member 68 for movement with respect thereto parallelwith the movement of the member 68 with respect to the frame 46,engageable shoulders 72 on the member 68 and block 71 providing stopmeans limiting the movement of the block with respect to the member 68in the direction of guide opening movement of the member 68. See Figure17. The block 71 is bored longitudinally of the movement thereof andinwardly from the end thereof nearest the negative film guide, andmounted for sliding movement in this bore is a plungin the bore of theblock 71 yieldably urges the plunger 73 in the direction of guideclosing movement of the member 68 and the plunger engages the member 68to yieldably urge the same with respect to this direction. A manuallyoperated lever 75 is pivotally mounted on the frame 46 on an axistransverse to the focal axis of the machine and is connected with theblock 71 by means of a toggle link device 76, whereby guide opening andclosing movement of the block '71 and' the member 68 is effected byopposite pivotal movements of the lever 75, guide closing movement ofthe member 68 being (affected through the resilient means including thespring 74 and guide opening movement of the member 68 being effectedthrough engagement of the shoulders 72 of the block 71 and member 68.The member 68 is locked in closed guide position by operating the togglelink device over center 5 against a stop formation 77 on the frame 46.

See Figures 14 and 16.

In order that the film in the negative film guide may be released duringintermittent movement thereof the following mechanism is provided. Asecond block 78 is mounted on the member 68 for adjustment with respectthereto parallel to the movement of the member 68, and an adjustmentscrew 79 extending longitudinally of the movement of the member 68 isscrewthreaded on the member 68 and is provided with a groove 81 engagedin a yoke formation 82 of the block 78 for adjustably positioning thisblock with respect to the member 68. A roller 83 is rotatably mounted onthe block 78, and an axial cam 84 fast on the cam shaft 21 is en gagedby the roller 83 when the member 68 is in closed guide position tooperate the member 68 against the spring 74 to release the film 59 inthe negative film guide during intermittent movement thereof, the cam 84being suitably timed with the cams 64 and for this purpose. Thesimplicity and effectiveness of this arrangement is apparent, and itwill be observed that the mechanism for intermittently releasing thefilm in the guide does not interfere with or require additional manualmanipulation for opening and closing the guide.

A ruby glass light shutter mounted within the frame 2 for movement intoand out of position between the ground glass 41 and the condenser 44 tointerrupt the printing light to the aperture. of the negative filmguide. See Figures 14 to 17, 19 and 24. This shutter is controlled inthe following manner to interrupt the printing light when the negativefilm guide is open for preventing the egress of printing light fromtheopened guide with a view toward dark rooni operation of the machine.A rod 86 is carried for longitudinal movement on the frame 2, and thisrod is provided with a cam 87 cooperating with a cam engaging formation88 on the shutter 85 to operate the shutter into position to interruptthe printing light to the aforementioned film guide when the rod 86 ismoved in the direction of guide closing movement of the member 68, theshutter moving out of printing light interrupting position under theinfluence of gravity when the'rod 86 and cam 87 are moved in theopposite direction. The lever is pivotally mounted on the frame 2 bymeans of ashaft 89 on one end the lever is secured and which extendsthrough and is journaledfin a bore of the frame. See Figures 16, 17, and19. A radially extending pin 91 is secured on the op-- posite end of theshaft 89 and a lever 92 is journaled on this shaft between the frame 2and thepin 91, a. coiled compression spring 93 encircling the shaftbetween the lever 92 and the frame 2 and yieldably urging the lever 92against the pin 91. The outer end of the lever 92 is connected with therod 86 is pivotally of which names? for operating the same by means of agrobved collar and pin connection 94 so that pivotal movement of thislever efi'ects operation of the shutter 85. A spring pressed 'frictiondevice .95 on the frame 2 engages the rod 86 to retard operation of therod, and a stop collar 96 is secured on the rod 86 for engagement withthe frame 2 to limit movement of the rod in the direction by which itoperates the shutter 85 into printing light interrupting position. Theend of the hub of the lever 92 engaging the pin 91 is provided withanotch 97 releasabl engageable with ate the shutter is as follows.

the pin for operatin the ever 92 to actuate the shutter 85 and t earrangement to actumechanism is shown in closed film guide position withthe toggle link device 76 in locked position against the stop 77. Inthis position of the manipulating lever 75 and the shaft 89 the pin 91is operatively engaged in the notch 97 of the lever 92 by reason of thespring 93, the shutter 85 being out of its printing light interruptingposition. Initial film guide opening movement of the lever 75 moves thetoggle link device over center to unlock, and the pin 91 engaged in thenotch 97 operates the lever 92 to actuate the rod 86 and cam 87 thereofto move the shutter 85 into printing light interrupting position, thisaction takin place before actual opening of the negative lm guide. Atthe time when the shutter 85 is in printing light interrupting positionthe collar 96 engages the frame 2 to prevent further. movement of therod 86 in the same direction. Further guide opening movement of thelever 75 effects opening of the guide, and further movement of the lever92 being prevented, the'pin 91 disengages from the notch 97 by movementof the lever 92 along the shaft 89' against.

the spring 93 to permit the further guide opening movement of the lever75, the pin moving with respect to the lever 92 during this movement ofthe lever 75. Upon 'movement of the lever 75 from opened guide positionto close the guide, the lever 92 is not actuated by reason of the brakedevice 95 until the pin 91 re-engages the notch 97 after which the lever92 is actuated to o erate the rod 86 to move the shutter 85 out oprinting light interruptin position, the shutter being so moved after te guide is closed and durthe shutter 85 and the ing final guide closingor lockin movement of the lever 75. Thus it will be 0 served that ideare controlled by one manually control ed member and that the shutter ismoved to printing li ht interrupting position before the guide is openedand out of this position after the guide is closed. Q g

Constant feed film sprockets 101 are spaced above and below the tubularmember 68 in film feeding alignment with the negative film guide, andthese sprockets are mounted on the As shown the.

film to and from the guide. In the operation of the machine the negativefilm 59 is fed 1 from an upwardly disposed film spool 107 over an upperguide roller 108 to the upper film sprocket 101. See Figure 1. From theupper film sprocket the film leads to the upperend of the negative filmguide in the form of a compensating loop. .From the lower end of thisguide the film leads to the lower film sprocket 101 in the form of acompensating loop, and from thissprocket it leads over a lower guideroller 108 on to a downwardly disposed film spool 107 which is drivenfrom the lower sprocket spindle by a belt and pulley drivingdevice 109to rewind the film, this device being adapted to slip to compensate fordifferent diameters of the roll of fihn on this spool. See Figure 2. Thefilm is retained on the film sprockets by means of releasable filmretaining roller devices 110. See Figures 1, 14, and 20.

The upper sprocket spindle 102 is axially bored; and extending throughthe bore of this spindle is a longitudinally movable rod 111.

See Figures 14 and 20. The outer end of this rod is turned at rightangles to the main portion thereof and has a roller 112 mounted thereonwhich is engageable with the outer edge of the negative film 59 on thesprocket.

A normally open electric switch 113 of the.

spring blade breaker type is mounted within t e frame 2 adjacenttheinner end of the rod 111 and is associated with the inner end of thisrod to be closed with inward movement of the rod. A fiat spring 111 hasone end secured stationarily with the switch 113 and engages atransverse groove 115 on the rod 111 inwardly beyond the inner end ofthe associated s indle 102 to urge the rod inwardiv to close t e switch113 and to prevent rotation of the rod. The spring 114 yieldably urgesthe rod 111 in the direction to engage the roller 112 with the outeredge of the film 59 on the upper sprocket 101, and this engagementnormally maintains the rod in an outer position with the switch 113opened. The

outer edge of the film 59 is provided with notches 116 s aced therealongin correspondence with ad ustments, such as printing light variations,to be made during the printing operation, and upon the roller 112encounter.- ing each notch, the spring 114 operates the rod 111 inwardlyto close the switch 113, the

switch being again opened as the roller disengages from the engagednotch and again engages the normal edge of the film.

- The switch ll3 as controlled by the notched 1 negative film 59 isutilized for stoppingop eration of the printing operation for adJustment of the printing light and for indicating the adjustment of theprintin light in the following manner. As herein efore described thepositive driving clutch consisting of the clutch teeth 23 and 27 isengageable and disengageable by axial movement of the hub 24,. thespring 28 yieldably urging the clutch into engagement-and normallymaintainin it so engaged. See Figures 12 and 15. member 24, which isrotatably fixed with the driven element of the clutch, i; e. the clutchteeth 23 on the cam disk 22, is an axial segment cam 117. Mounted forlon itudinal movement radially of the hub mem er 24 is a verticallydisposed bar 118 movable into and out of the path of the cam 117. SeeFigures 12, 13, and 24. A spring 119 yieldabl urges the bar 118downwardly into the pat of the cam 117 and when in this position,- seeFigure 13, the cam 117 engages the same and reacting thereagainstdisengages the clutch with angular movement of the driven clutch memberby axially moving the hub member 24 and with it the gear 26 and theclutch teeth 27, forming the drlvin member of the clutch,

'- to disengage the clutc against the influence trigger member 121pivotally mounted on the of the spring 28. When the bar 118 is movedupwardly outof engagement with the cam 117 the spring 28 engages theclutch. A

' frame 2 normally maintains the bar 118 in an upper position out of thepath of the cam 117 and against the influenceof the spring 119 byreleasable engagement with a notch 122- i the spring 126 which causesthe rod 127 to strike the trigger member 121 and move the same againstthe influence of the spring device 123 out of engagement with the notch122 of the bar 118 whereupon the-spring 119 moves the bar downwardlyinto the path of the cam 117 to disengage the driving clutch. Afterdisengagement of the driving clutch the clutch is re-engaged by manuallyoperating a spring push button device 128 provided with a cam formation129 engageable with a. similar cam formation 131 on the bar 118 to ormedon the outer end of the hub.

raise this bar to re-engage the trigger member with the notch 122 of thebar. A second manually operated push button device 132 is operable onthe trigger member 121 to dis engage the same from the notch 122 of thebai-l118 for disengaging the driving clutch at w1 Means for quicklystopping the film operating mechanism, and preferably for stopping it ata predetermined position in its cycle, upon disengagement of the drivingclutch is provided and will now be described. M ounted for verticalmovement below the cam disk 22 is a block 133 movable into and out offrictional engagement with the peripheral surface of this cam disk SeeFigures 12, 13, 22, and 23. Mounted in a vertical bore of the block 133for vertical movement with respect thereto is a plunger 134. The upperend of this plunger is reduced and the upper end of the bore of theblock is correspondingly reduced to provide opposing shoulders 135limiting upward movement of the plunger with respect to the block. Aspring 136 is disposed in the bore of the block 133 below the plunger134 and is arranged between the plunger and a screw 137 screwthreadedinto the bottom of the bore of the blockto yieldably urge the plungerupwardly with respect to the block which movement is limited by theshoulders 135. See Figure 13. Normally theblock 133 is so positionedthat neither the block nor the upper end of the plunger 134, whichnormally projects above the block, are engaged with the peripheralsurface of the cam disk 22. See Figure 12. A lever 138 is pivotallymounted on an axis transverse to and immediately below the gear 26 andis connected with the block 133 for operating the block 133 and plunger134 vertically into and out of engagement with the peripheral surface ofthe cam disk 22. The lever 138 is pivotally carried and'the block 133 iscar ried for relative vertical movement on a mounting member 139 whichis mounted on the frame 2 for vertical adjustment by means of a suitableadjusting device 141. A plunger 142 is mounted for longitudinal movementin a vertical bore of the mounting member for longitudinal movement in avertical of the -mounting memb er 139 and is yieldably urged upwardly bya spring 143 in this bore and mterposed between the lower end of theplunger 1 and anadjusting screw 144 screwthreaded into the lower end ofthe bore of the member 139. The plunger 142 is directly below the axisof the lever 138 and under the influence of the spring 143 the upper endof the plunger engages a chordal surface on the lever 138 to yieldablyurged the lever into a position in which the block 133 and the plunger134 are out of engagement with the periphery of the cam disk 22, asshown in Figure 12. The main portion of the lever 138 extends upwardlyfrom the axis thereof for engagement

